1. Field of the Invention
The present invention relates to an image processing device, a control method of the image processing device, and a storage medium for storing a program to execute the control method.
2. Description of the Related Art
Conventionally, as techniques for transmitting display image data to an operation display unit of an image processing device, following techniques have been proposed.
For example, Japanese Patent Application Laid-Open No. H10-319942 proposes a technique of providing on a display unit two memories corresponding to a whole display area of a display screen, and alternately changing over a display data reading source between the two memories to execute high-speed changeover of the display screen.
Further, Japanese Patent Application Laid-Open No. H11-024651 proposes a technique of reducing, in case of executing a rotation process to display data to be displayed on a display unit, a capacity of a memory by dividing the display data, reading each of the divided display data into the memory, and then executing the rotation process to each of the read display data.
However, in the above conventional techniques of the image processing device, in case of transferring the display data from the memory to the display unit, the image processing device transfers to the display unit the display data corresponding to the whole display area of the display unit. For this reason, an amount of the display data to be transferred to the display unit tends to increase.